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Abstract:

A method for operating a ship propulsion system, in particular a sailing
ship propulsion system, comprising an internal combustion engine (303),
at least one shifting clutch (319), and a drive device (309) for
transmitting drive power to at least one propeller (308). The direction
of thrust of the propeller (308) is changed via the drive device (309)
which is designed as a ship propulsion system which can be pivoted about
a substantially vertical control axis (320) by pivoting a thrust unit
(321) associated with the drive device (309). For this purpose, the
pivotable thrust unit (321) is pivoted approximately 180° in the
opposite direction to reverse the direction of thrust of the propeller
(108).

Claims:

1-9. (canceled)

10. A method of operating a hybrid drive system of a ship in which the
hybrid drive system comprises an internal combustion engine (103, 303)
and an electric machine (105), the electric machine (105) and at least
one shifting clutch (115, 116), form a drive unit, a drive device (109,
209, 309, 509) for transmitting drive power to at least one propeller
(108, 208, 308, 408, 508), the drive device (109), a drive unit (140),
power electronics (107), and a battery (106) form an electric hybrid unit
(101), an electric control unit (110) for controlling the internal
combustion engine (103) and the electric hybrid unit (101), the control
unit (110) determines different operating modes of the hybrid drive
system, and when a rotational direction of the electric machine (105) is
reversed, a direction of travel of the ship is reversed, the method
comprising the steps of: pivoting a thrust unit (121, 221, 321, 421,
521), associated with the drive device (109, 209, 309, 509), using the
drive device (109, 209, 309, 509) to change a direction of thrust of the
propellers (108, 208, 308, 408, 508), the drive device (109, 209, 309,
509) being a ship propulsion system that is pivotable about a
substantially vertical control axis (120, 220, 320, 420, 520); and if the
electric machine (105) fails, pivoting the pivotable thrust unit (121,
221, 321, 421, 521) approximately 180.degree. in an opposite direction to
reverse the direction of thrust of the propeller (108, 208, 308, 408,
508) such that the ship is maneuverable exclusively via the internal
combustion engine (103).

11. The method according to claim 10, further comprising the step of
recording a current first position of the thrust unit (121, 221, 321,
421, 521) in the electronic control unit, and, pivoting the thrust unit
from the current first position of the thrust unit by approximately
180.degree. into an opposite, second position, if a request to reverse
the direction of thrust is entered into the electronic control unit.

12. The method according to claim 10, further comprising the step of
adjusting a direction of thrust of the thrust unit (121, 221, 321, 421,
521) with a rudder device, and entering a request to reverse the
direction of thrust of the thrust unit (121, 221, 321, 421, 521) via a
selector lever (365) of a control device (370).

13. The method according to claim 11, further comprising the step of
positioning the selector lever (365) in a first adjustment range (360) to
position the thrust unit (121, 221, 321, 421, 521) in a first position,
and positioning the thrust unit (121, 221, 321, 421, 521) in a second
position, which is approximately 180.degree. opposite the first position,
when the selector lever (365) is positioned in a second adjustment range
(361), reversing the direction of thrust of the thrust unit (121, 221,
321, 421, 521) by moving the selector lever (365) from one of the first
and the second adjustment ranges (360, 361), past a middle position (M),
and into the other of the first and the second adjustment ranges (360,
361).

14. The method according to claim 10, further comprising the step of,
when the thrust unit (121, 221, 321, 421, 521) pivots from the first
position into the second position, discontinuing transmission of drive
power to the propeller (108, 208, 308, 408, 508).

15. The method according to claim 14, further comprising the step of
automatically disengaging a shifting clutch (115, 116, 319, 519), to
discontinue the transmission of drive power to the propeller (108, 208,
308, 408, 508), when a selector lever (365) is at a middle position (M)
upon moving from a first adjustment range (360) to a second adjustment
range (361), starting from a first position of the thrust unit (121, 221,
321, 421, 521); and when the selector lever (365) passes from the middle
position (M) and enters the second adjustment range (361), pivoting the
thrust unit (121, 221, 321, 421, 521) approximately 180.degree. into a
second position which is opposite the first position, and engaging the
shifting clutch (115, 116, 319, 519) once the thrust unit (121, 221, 321,
421, 521) reaches the second position.

16. The method according to claim 13, further comprising the step of
reducing the rotational speed of the internal combustion engine when,
starting from a first position of the thrust unit (121, 221, 321, 421,
521), moving the selector lever (365) to the opposite adjustment range to
a minimum value in the middle position (M) of the selector lever (365)
while the shifting clutch (319, 519) is disengaged, and, when the
selector lever (365) is moved further into the opposite adjustment range,
pivoting the thrust unit (121, 221, 321, 421, 521) into the opposite,
second position and then, once the shifting clutch (319, 519) engages,
increasing the rotational speed of the internal combustion engine (303)
in accordance with the deflection of the selector lever (365) in the
particular adjustment range.

17. A drive device for implementing a method of operating a hybrid drive
system of a ship, in which the hybrid drive system comprises an internal
combustion engine (103, 303) and an electric machine (105), the electric
machine (105) and at least one shifting clutch (115, 116) forms a drive
unit, a drive device (109, 209, 309, 509) for transmitting drive power to
at least one propeller (108, 208, 308, 408, 508), the drive device (109),
a drive unit (140), power electronics (107) and a battery (106) form an
electric hybrid unit (101), an electric control unit (110) for
controlling the internal combustion engine (103) and the electric hybrid
unit (101), the control unit (110) determining different operating modes
of the hybrid drive system and, when a rotational direction of the
electric machine (105) is reversed, a direction of travel of the ship is
reversed, the method comprising the steps of pivoting a thrust unit (121,
221, 321, 421, 521), associated with the drive device (109, 209, 309,
509), using the drive device (109, 209, 309, 509) to change a direction
of thrust of the propellers (108, 208, 308, 408, 508), the drive device
(109, 209, 309, 509) being a ship propulsion system that is pivotable
about a substantially vertical control axis (120, 220, 320, 420, 520),
pivoting the pivotable thrust unit (121, 221, 321, 421, 521)
approximately 180.degree. in an opposite direction to reverse the
direction of thrust of the propeller (108, 208, 308, 408, 508) such that
the ship is maneuverable exclusively via the internal combustion engine
(103) if the electric machine (105) fails, the drive device comprising:
the drive device being in the form of a rudder propeller which includes a
transmission unit (122, 222, 322, 522) fixedly disposed within a hull
(130, 230, 330, 430); the thrust unit (121, 221, 321, 421, 521) being
situated underneath the hull and pivotable about the substantially
vertical control axis (120, 220, 320, 420, 520); and shafts (104, 123,
124, 204, 223a, 223b, 224) being arranged in a shape of a "Z" and
disposed within the drive device (109, 209, 309, 509) in a rotatable,
interconnected manner to transmit power from the internal combustion
engine (103, 303) to the propeller (108, 208, 308, 408, 508).

18. The drive device according to claim 17, wherein the thrust unit (121,
221, 321, 421, 521), including the propeller shaft (124, 224) mounted
thereon as well as a direction of thrust of the propeller (108, 208, 308,
408, 508), being pivotable at least 360.degree. about the substantially
vertical control axis (120, 220, 320, 420, 520).

[0002] The invention relates to a method for operating a ship propulsion
system, in particular of a sailing ship, and a drive device therefor.

BACKGROUND OF THE INVENTION

[0003] Sailing ships require an additional propulsion system when wind
conditions are insufficient to propel the sailing ship, or when maneuvers
are carried out for docking and undocking. Sailing ship propulsion
systems in which an internal combustion engine drives a propeller are
known. The internal combustion engine is usually in the form of a diesel
engine. In the motor mode, the sailing ship is steered using a rudder
blade which is also used for steering in the sailing mode.

[0004] The catalog entitled "Integrated Starter Motor Generators" from the
company Iskra Avtoelektrika, which is the owner of SI 22377 A, shows a
ship propulsion system which comprises a parallel hybrid drive of the
type described in SI 22377 A, and a stern drive. A Z-shaped, two-fold
redirection of the drive train to the propeller takes place in the stern
drive via two bevel gear systems. The first clutch is in the form of a
multi-disk clutch or claw clutch. This parallel hybrid drive can be used
to select the following operating modes: in a starter operating mode, the
first clutch is engaged and the second clutch is disengaged. In this
case, the electric machine functions as a starter and starts the internal
combustion engine. As soon as the internal combustion engine is running,
the drive system is automatically switched via the electronic control
unit to the generator mode, in which the first clutch is likewise engaged
and the second clutch is disengaged. The internal combustion engine
drives the electric machine which functions as a generator and therefore
charges the battery. Optionally, the battery can be charged via the
electric power grid using the converter-charging unit while the ship is
docked in the harbor. In the electric drive mode, the first clutch is
disengaged and the internal combustion engine idles. The second clutch is
engaged and therefore the electric machine, which now functions as a
motor, drives the propeller. In a so-called booster mode, both clutches
are engaged and the electric machine and the internal combustion engine
operate in parallel. The cumulative drive power of the two machines
drives the propeller.

[0005] In the stern drive shown, the direction of thrust of the propeller
is reversed by reversing the propeller rotation, which may be necessary,
for instance, to reverse the direction of travel when docking or
undocking. To this end, a double-cone clutch which can be switched
between the two directions of rotation is provided to change the
rotational direction of the propeller. The solution with the double-cone
clutch includes additional components and is difficult to assemble, which
are disadvantages. Moreover, the shifting procedure is accompanied by
poor shifting behavior in the form of torque surges and the associated
material stress, as well as jerky propulsion and an audible noise. A
further disadvantage associated with reversing the direction of thrust by
reversing the rotational direction of the propeller is the reduced
efficiency in the conversion of mechanical energy into energy of flow
since the propeller blade geometry is typically designed or optimized for
only one rotational direction.

SUMMARY OF THE INVENTION

[0006] The problem addressed by the invention is that of providing a
method for the efficient, reversible propulsion of a ship, in particular
a sailing ship, and creating a structurally simple drive device therefor.

[0007] A ship propulsion system, in particular a sailing ship propulsion
system, comprises an internal combustion engine, at least one shifting
clutch, and a drive device for transmitting drive power to at least one
propeller. Therefore, in a method according to the invention, the drive
device which is in the form of a ship propulsion system which can pivot
about a substantially vertical control axis is used to change the
direction of thrust of the propeller by pivoting a thrust unit associated
with the drive device. This design of a drive device is also referred to
as a rudder propeller.

[0008] The pivotable thrust unit is pivoted approximately 180° in
the opposite direction to reverse the direction of thrust of the
propeller. As a result, it is possible to reverse the direction of thrust
of the propeller without changing the rotational direction of the
propeller. The potential to reverse the direction of thrust in such a
manner is advantageous for maneuvering in particular. In contrast to the
prior art, an additional double clutch or reversing clutch, which has the
stated disadvantages in regard to noise, shifting behavior, design
complexity and costs, is not required in the drive device in order to
reverse the direction of thrust. Moreover, the pivotable ship propulsion
system permits the propeller thrust to be steered in any direction,
thereby making it possible not only to reverse the direction of travel,
but also to perform any maneuver. In particular, a lateral thrust
component, i.e. a direction of thrust which does not lie in the
longitudinal direction of the ship, can be generated without a cross jet
propeller. A further advantage of a reversal of the direction of thrust
without changing the rotational direction of the propeller is good
propulsion efficiency and effective conversion of mechanical energy into
energy of flow at the propeller. The reason for this is that the optimal
configuration of the propeller blade geometry is designed for only one
direction of rotation. In an opposite direction of rotation of the
propeller, the efficiency of energy conversion is poorer than in the
rotational direction for which the propeller blade geometry was designed
and optimized.

[0009] In an advantageous embodiment of the method according to the
invention, a current first position of the thrust unit is recorded in an
electronic control unit. If a request to reverse the direction of thrust
is entered into the electronic control unit, the thrust unit is pivoted
from the current first position of the thrust unit by approximately
180° into an opposite, second position. As a result, the direction
of thrust can be reversed from any position of the pivotable ship
propulsion system, such as when the direction of thrust is transverse to
the longitudinal axis of the ship, which is required, inter alia, when
docking.

[0010] Furthermore, it is possible to adjust the direction of thrust of
the thrust unit using a rudder device, and to enter the request to
reverse the direction of thrust using a selector lever of a control
device.

[0011] Alternatively thereto, the control device can also be in the form
of a joystick, a sliding regulator, an actuator wheel, or an adjustment
function on a screen or a panel with a touchscreen. Another possibility
would be to integrate the function of the control device in the function
of a further control device for other components.

[0012] According to a preferred embodiment of the method, when the thrust
unit is in a first position, the selector lever is in a first adjustment
range and, when the thrust unit is in a second position which is opposite
the first position, the selector lever is in a second adjustment range.
To reverse the direction of thrust, the selector lever is moved from the
particular position of the thrust unit, past a middle position, and into
the particular other adjustment range.

[0013] Within this framework it is possible to adjust the rotational speed
of the internal combustion engine and, therefore, the rotational speed of
the propeller by displacing the selector lever within the particular
adjustment range. This results in the advantage that the request to
reverse the direction of thrust and the adjustment of the propeller or
engine speed are now combined in a single control device.

[0014] According to a particular embodiment of the method, in a first
position of the thrust unit, the propeller thrust is directed astern to
propel the ship forward and, in a second position of the thrust unit
opposite the first position, the propeller thrust is directed toward the
bow to propel the ship in reverse. It is therefore possible to reverse
from forward to backward and vice versa without changing the rotational
direction of the propeller, and without the associated disadvantages.

[0015] In a particularly advantageous variant, the propeller is not driven
while the thrust unit is pivoted from the first position into the second
position. An undesired transverse force component, which would impair the
maneuvering behavior and create a potentially dangerous situation while
the ship is maneuvered, is thereby prevented.

[0016] Within this framework it is possible for the shifting clutch to
disengage automatically in order to interrupt the propeller drive when
the selector lever reaches the middle position when being moved from a
first adjustment range to a second adjustment range starting in the first
position of the thrust unit. When the middle position is subsequently
passed through and the second adjustment range is entered, the thrust
unit is pivoted approximately 180° into a second position opposite
the first position. The shifting clutch is re-engaged once the thrust
unit has reached the second position.

[0017] Moreover, once the shifting clutch has engaged, the rotational
speed of the internal combustion engine is increased once more in
accordance with the deflection of the control device.

[0018] In addition, it is possible to reduce the rotational speed of the
internal combustion engine when the selector lever is moved to the
opposite adjustment range, starting from a first position of the thrust
unit, and to assume a minimum value when the selector lever is in the
middle position, while the shifting clutch is disengaged. When the
selector lever is moved further into the opposite adjustment range, the
thrust unit is pivoted into the opposite, second position. Once the
shifting clutch has engaged, the rotational speed of the internal
combustion engine is increased in accordance with the deflection of the
control device.

[0019] As an alternative thereto, it is possible to suppress the
disengagement and engagement of the shifting clutch using an additional
operating device, whereby the reversing procedure takes place more
rapidly, although with the disadvantage of impaired maneuverability due
to the rotating propeller thrust.

[0020] It is possible that the drive device for implementing the method
according to the invention be in the form of a pivotable ship propulsion
system which is also referred to as a rudder propeller. It comprises a
transmission unit which is fixedly disposed within a hull, and a thrust
unit which is situated underneath the hull and can pivot about a
substantially vertical control axis. To transmit power from the internal
combustion engine to the propeller, shafts arranged in the shape of a "Z"
are disposed within the drive device in a rotatable, interconnected
manner. The pivotable ship propulsion system advantageously makes it
possible to direct the thrust generated by the propeller in order to
steer the ship.

[0021] In an advantageous embodiment of the drive device, it is possible
to pivot the thrust unit, including the propeller shaft mounted thereon,
and, therefore, the direction of thrust of the propeller at least
360° about the substantially vertical control axis.
Advantageously, any direction of thrust required to maneuver the sailing
ship can be attained using a pivot angle of at least 360°. In
addition, the direction of thrust of the drive unit can be reversed into
the opposite direction from any position of the thrust unit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Embodiments of the invention are depicted in the drawings and are
described in greater detail in the following.

[0023] The drawings show:

[0024] FIG. 1 a schematic depiction of a hybrid system of a ship according
to the invention,

[0025] FIG. 2 a schematic depiction of a sailing ship comprising the ship
propulsion system according to the invention,

[0026] FIG. 3 a schematic depiction of the drive train of the ship
propulsion system according to the invention,

[0027] FIG. 4 a schematic depiction of a control device of the ship
propulsion system according to the invention,

[0028] FIG. 5 a sectional view of a drive device according to the
invention,

[0029] FIG. 6 a perspective depiction of the drive device and the electric
machine,

[0030] FIG. 7 a schematic depiction of a sailing ship comprising the ship
propulsion system according to the invention, in the sailing mode,

[0031] FIG. 8 a schematic depiction of a ship comprising a pivotable ship
propulsion system and the control device during travel forward,

[0032] FIG. 9 a schematic depiction of a ship comprising a pivotable ship
propulsion system and the control device during travel backward, and

[0033] FIG. 10 schematic top view of a ship in which propeller thrust is
directed to propel the ship in a first direction;

[0034] FIG. 11 a schematic top view of a ship in which propeller thrust is
redirected to propel the ship in second direction opposite the first
direction depicted in FIG. 10, and

[0035] FIG. 12 a sectional drawing of an embodiment of a ship propulsion
system according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] FIG. 1 shows a schematic depiction of a hybrid drive system of a
ship according to the invention. By definition, a hybrid drive system
contains at least two energy converters, each of which has an energy
accumulator system. The hybrid drive system according to the invention
comprises an internal combustion engine 103 having a fuel tank 102 as an
energy accumulator, and an electric machine 105 comprising a battery 106
as an energy accumulator. The hybrid drive system is designed as a
so-called parallel hybrid, that is, as an option, both the internal
combustion engine 103 and electric machine 105 can drive the output drive
directly, i.e. a propeller 108 in this case.

[0037] The electric machine 105, in combination with a shifting clutch 115
and a shifting clutch 116, forms a drive unit 140. The drive unit 140, in
combination with power electronics 107, the battery 106, and a drive
device 109, forms an electric hybrid unit 101. The drive device 109
drives a propeller 108. The internal combustion engine 103 and the
electric hybrid unit 101 are controlled by an electronic control unit 110
via the electrical connections 111 and 112, wherein the control unit 110
determines different operating modes of the hybrid drive system.

[0038] The shifting clutch 115 is disposed between the electric machine
105 and an output shaft 114 of the internal combustion engine 103, and
the shifting clutch 116 is disposed between the electric machine 105 and
an input shaft 104 of the drive device 109. The electric machine 105, the
internal combustion engine 103, and the drive device 109 can be connected
to one another in a rotationally fixed manner via the shifting clutches
115 and 116.

[0039] The electric machine 105 can be operated as a generator or a motor
independently of the particular operating mode, depending on the
actuation. In the generator mode, the battery 106 is charged by power
electronics 107. When the charge direction 113 is reversed, the electric
machine 105 is operated as a motor using the electric energy accumulated
in the battery 106.

[0040] In a driving range with a moderate to high speed of the ship, both
shifting clutches 115 and 116 are engaged, and the internal combustion
engine 103 can drive the propeller 108. In this position of the shifting
clutches 115 and 116, the electric machine 105 can be operated as a
generator, and therefore the internal combustion engine 103 drives both
the propeller 108 and the electric machine 105, and therefore charges the
battery 106. Likewise, when the battery 106 is sufficiently charged, it
is also feasible to operate the electric machine 105 as a motor, wherein
the drive power of the internal combustion engine 103 and the electric
machine 105 add up and can therefore cover brief peak demands for drive
power; this is also referred to as "booster mode". In the same
constellation, the internal combustion engine 103 can also be relieved by
the additional power of the electric machine 105. Since the internal
combustion engine 103 is operated at relatively high loads when the ship
is traveling at a moderate to high speed, the operating point of the
internal combustion engine 103 is located in or near the minimal
consumption range. The electric machine 105 can also be shut off via the
electronic control unit 110 or the power electronics 107 and then be
driven without load by the internal combustion engine 103.

[0041] If the shifting clutch 115 is engaged and the shifting clutch 116
is disengaged, the internal combustion engine 103 can drive the electric
machine 105 and, with this as the generator, charge the battery. This
operating mode can be selected when the ship is at a standstill or when
sailing. If the shifting clutches 115 and 116 are in the same position,
the internal combustion engine 103 can be started up with the electric
machine 105, which acts as a starter, in the motor mode.

[0042] The ship can be driven electrically by disengaging the shifting
clutch 115 and engaging the shifting clutch 116. The electric machine 105
is driven by the electrical energy accumulated in the battery 106 when so
actuated by the electronic control unit 110 or the power electronics 107,
and the internal combustion engine 103 is shut off. An electric drive is
advantageous at low ship speeds in particular since, under these
conditions, the operating point of the internal combustion engine 103 is
situated far from the minimal consumption range. In addition, quiet and
exhaust-free operation of the ship propulsion system is thereby made
possible in surroundings subject to noise or environmental regulations.

[0043] A further advantage of the electric drive is the possibility of
reversing the rotational direction of the electric machine 105 in order
to reverse the direction of travel of the ship. This is a great advantage
when maneuvering, for example. For instance, a reverse coupling can be
omitted in the drive device 109, in contrast to the prior art. In
addition, the electric drive makes sensitive maneuvering possible since
the rotational speed of the electric machine 105 and, therefore, the
rotational speed of the propeller can be changed up to the point of
standstill.

[0044] Moreover, one more operating mode can be attained when the two
shifting clutches 115 and 116 are in the shift position described. In the
sailing mode, the propeller 108 acts as a turbine due to the movement of
the ship through the water, and drives the electric machine 105 via the
drive device 109 and the engaged shifting clutch 116, whereby it is
operated as a generator and charges the battery 106. This option is
particularly advantageous since the electrical energy is ultimately
created by wind power, without fuel consumption and the associated
environmental impacts.

[0045] Since driving the electric machine 105 using the propeller 108
generates drag, the sailing ship loses speed in this operating mode. For
this reason, the battery 106 is charged using wind energy only at a
defined minimum speed or above; below this point the propeller 108 can be
allowed to rotate without load by disengaging the shifting clutch 116.

[0046] If, in the sailing mode, the battery 106 is fully charged and the
shifting clutch 116 is disengaged to allow the propeller 108 to rotate
without load, a disadvantageous operating noise is produced by the drive
device 109 rotating without load. To prevent this, the electric machine
105 can be actuated in such a manner that it builds up torque. The
propeller 108 is brought to a standstill via appropriate control of the
electric machine 105 which is operated as a motor.

[0047] FIG. 2 shows a schematic depiction of a stern section of a sailing
ship comprising the ship propulsion system according to the invention. An
arrow 150 indicates the forward travel direction. An internal combustion
engine 103, on which a drive unit 140 designed as a hybrid module is
mounted, is disposed in a hull 130. The drive device 109, which is
downstream in the flow of force, drives the propeller 108. The drive
device 109 comprises a transmission unit 122, which is fixedly disposed
within the hull 130, a thrust unit 121, and a control drive 129. The
thrust unit 121 is disposed underneath and outside of the hull 130 at the
transmission unit 122, in a manner such that it can pivot about a
vertical control axis 120, wherein the thrust unit 121 is moved by the
control drive 129. A rudder 131 for steering the sailing ship in the
sailing mode is pivotably disposed on the stern end of the hull 130. If
the sailing ship is driven in the motor mode by the hybrid drive or the
propeller 108, the sailing ship is steered by pivoting the thrust unit
121. Advantageously, any direction is therefore feasible, which is highly
advantageous for maneuvering in particular. To reverse the direction of
travel, in the normal case the internal combustion engine 103 is shut off
and the rotational direction of the electric machine 105 is reversed, and
so the propeller 108 also rotates in the opposite direction. It is
therefore possible to reverse in a precise manner, especially since the
electric machine 105 can be started from a standstill. When the propeller
108 is driven using the internal combustion engine 103, it can rotate in
only one direction. If the electric machine 105 has failed and the
sailing ship must be maneuvered exclusively using the internal combustion
engine 103, the thrust unit 121 is pivoted in the opposite direction.

[0048] FIG. 3 shows a schematic depiction of the drive train of the ship
propulsion system according to the invention. As presented above with
reference to FIG. 1, the internal combustion engine 103 is connected to
the drive unit 140 via an output shaft 114. The rotational movement of
the hybrid drive is introduced into the drive device 109 via the input
shaft 104. The drive device 109 includes the shafts 104, 123 and 124,
which are arranged in the shape of a "Z", and two bevel gear systems
which couple the shafts to one another, and which is formed by a bevel
gear 125 and 126, and a bevel gear 127 and 128. Within the drive device
109, the bevel gear 125 is disposed on the input shaft 109 in a
rotationally fixed manner. The bevel gear 125 is engaged with a bevel
gear 126 which is disposed on a shaft 123 at the upper end thereof in a
rotationally fixed manner. The rotational axis of the shaft 123 is the
substantially vertical control axis 120. The bevel gear 127 is disposed
thereon in a rotationally fixed manner at the lower end of the shaft 123.
The bevel gear 127 is engaged with the bevel gear 128, wherein the bevel
gear 128 is disposed on one end of the shaft 124 within the drive device
109 in a rotationally fixed manner. At the other end of the shaft 124,
outside of the drive device 109, the propeller 108 is connected to the
shaft 124 in a rotationally fixed manner. Since, in the normal case, the
direction of travel is reversed using the electric machine 105, a reverse
coupling in the drive 109 is not required. If the electric machine 105
fails and the direction of travel should be reversed, e.g. to perform
docking or undocking maneuvers, this can be accomplished by pivoting the
thrust unit 121 shown in FIG. 2.

[0049] FIG. 4 shows a schematic depiction of a control device of the ship
propulsion system according to the invention. The control device includes
a control drive 129, a planetary transmission 138, an auxiliary
transmission 139, and a control shaft 117. The control shaft 117 is
connected to the thrust unit 121 (not depicted) in a rotationally fixed
manner. An external gearwheel 118 is connected to the control shaft 117
in a rotationally fixed manner on an outer contour thereof. The control
drive 129 comprises an electric motor 133, a brake 136, and an emergency
actuation mechanism 137. To set a desired course of the sailing ship, the
thrust unit 121 must be pivoted by a certain angle about the control axis
120. To this end, a control signal turns on the electric motor 133 and
the control drive 129. Since an electric motor generally rotates
relatively rapidly, but the pivoting motion of the thrust unit 121 must
take place with great angular accuracy, the rotational speed of the
electric motor 133 is reduced via the planetary transmission 138 and the
auxiliary transmission 139 to the required angular velocity of the
control shaft 117. To this end, the electric motor 133 drives a sun gear
141 of the planetary transmission 138. A ring gear 143 is held, and so
the output drive from the planetary transmission 138 takes place via the
planet carrier 142. The thusly reduced rotational speed is now reduced
further in the auxiliary transmission 139 via a spur gear stage 144 and a
spur gear stage 145. The output of the auxiliary transmission 139 takes
place via the gearwheel 118 directly to the control shaft 117 to which
the gearwheel 118 is connected in a rotationally fixed manner. If the
desired position of the thrust unit 121 has been reached, the electric
motor 133 is shut off and the thrust unit 121 is prevented via the brake
136 from rotating in a self-acting manner, which is undesired. If the
electric motor 133 fails, the control drive 129 can be actuated
mechanically using the emergency actuation mechanism 137, thereby
enabling a course to be set in a makeshift manner.

[0050] FIG. 5 shows a sectional view of a drive device 209 according to
the invention.

[0051] The drive device 209 comprises a transmission unit 222 and a thrust
unit 221. The transmission unit 222 is fixedly disposed above and within
a hull 230. The thrust unit 221 is mounted in the transmission unit 222
such that it can pivot about a control axis 220. The transmission unit
222 comprises a control drive 229 which includes an electric motor 233, a
brake 236, and an emergency actuation mechanism 237. The mode of
operation of the brake 236 and the emergency actuation mechanism 237 were
described with reference to FIG. 4. A bevel gear 225 on an input shaft
204 is engaged with a bevel gear 226 on a shaft 223a and drives it as
well as an adjacent shaft 223b in the thrust unit 221. The shafts 223a
and 223b are interconnected in a form-locking manner, and both rotate
about the control axis 220. The shaft 223b is connected in the thrust
unit 221 via a bevel gear 227 and a bevel gear 228 to a shaft 224,
wherein a propeller 208 is connected in a rotationally fixed manner to
the shaft 224 at one end thereof outside of a housing 234. The shaft 223b
is rotatably disposed in a shaft channel 232. A supply of lubricant is
provided inside the shaft channel 232, which serves to lubricate the
bearings and gearing 225, 226, 227 and 228. A cooling channel 235 is
formed between the shaft channel 232 and the housing 234, into which
water surrounding the thrust unit 221 seeps. The water serves as a
cooling medium for the power-transmitting parts of the drive device 209.
The thrust unit 221 is driven via the control drive 229, the electric
motor 233 of which drives--via a planetary transmission, which is not
depicted, and an auxiliary transmission which is shown only in part--a
gearwheel 218 and, therefore, a control shaft 217 with the thrust unit
221 connected thereto.

[0052] FIG. 6 shows a perspective view of the drive device 209 which
comprises the thrust unit 221 with the propeller 208 and the transmission
unit 222. The drive device 209 is mounted on a drive unit 240 in this
depiction. Power electronics 207 are disposed directly on the drive unit
240. The direct connection of all components results in a compact hybrid
drive. The direction of thrust of the propeller 208 can be changed in the
manner described with reference to FIGS. 2 to 5, which results in the
positive effect of good propulsion efficiency as well as good
maneuverability, in particular when docking and undocking.

[0053] FIG. 7 shows the schematic depiction of a stern section of a
sailing ship comprising the drive device 109 according to the invention.
An arrow 150 indicates the forward travel direction. The features shown
correspond to those in FIG. 2. The thrust unit 121 is pivoted in the
opposite longitudinal direction compared to the depiction in FIG. 2. This
position of the thrust unit 121 makes two operating modes possible, and
advantageously affects them. The first operating mode is travel backward
with the internal combustion engine 103 as the drive, which is only
necessary in exceptional cases, however, such as when the electric
machine 105 fails. Since the internal combustion engine 103 cannot change
its own rotational direction nor, therefore, that of the propeller 108,
the thrust of the propeller 108 is directed by pivoting the thrust unit
121 in the opposite direction, thereby making it possible to reverse the
direction of travel.

[0054] Another operating mode, in which the thrust unit is pivoted
approximately 180° from the drive direction into the opposite
direction, which occurs during straight-ahead travel, for example, is
that of charging the battery in the sailing mode. In this case the
propeller 108 operates as a turbine which is driven by the water being
passed through, thereby driving the electric machine 105. It is operated
as a generator in this operating mode, and the electrical energy that is
generated is accumulated in the battery, where it is available for quiet
and exhaust-free operation of the electric machine 105, or for operation
of on-board devices. In order to be able to attain all necessary
directions of thrust, the thrust unit 121 must be capable of pivoting at
least 360°.

[0055] Maneuverability is increased even further via a combination of the
ship propulsion system according to the invention with a cross jet
propeller (not depicted) which is preferably disposed in the bow of the
hull 130.

[0056] The vanes of a propeller have a certain geometry of curvature,
which was designed for a defined rotational direction to optimally
convert drive energy into thrust. If the propeller is now operated as a
turbine driven by the water being passed through in the same orientation
it assumed for driving, then the conversion of energy of flow into drive
energy for the electric machine 105, which is operated as a generator, is
inefficient since the flow impacts the side of the propeller vanes that
do not have a favorable design for this operation. If the propeller 108
is oriented in the opposite direction by pivoting the thrust unit 109,
the flow forces act on the side of the vane that has a more favorable
design for energy conversion, and a greater amount of electrical energy
can be generated. Since a sailing ship is subject to a certain lateral
drift in the sailing mode, the direction of travel does not always
coincide with the longitudinal direction of the sailing ship. In this
case the propeller 108, which is operated as a turbine, would be impacted
by flow at an angle, which is detrimental to energy conversion. In
addition, a compression of the drift would therefore be possible here in
that the drift and, therefore, the actual direction of travel of the
sailing ship are measured or calculated, and the thrust unit 109 is
oriented by an appropriate pivot angle into the actual direction of
travel. The drift can be measured using GPS data or radar-supported data,
for example.

[0057] FIG. 8 shows a schematic depiction of a ship, which is shown only
in part, comprising an internal combustion engine 303, a pivotable ship
propulsion system 309, which is also referred to as a rudder propeller,
and a control device 370 in the form of a selector lever 365, when
traveling forward. Alternatively, the control device 370 can also be in
the form of a joystick, a keyboard, an actuator wheel, a sliding
regulator, or a panel with a touchscreen.

[0058] A drive device 309 disposed in a hull comprises a shifting clutch
319, a transmission unit 322, a thrust unit 321 which can pivot about a
substantially vertical control axis 320, and a control drive 329 via
which the thrust unit 321 is pivoted. In the example shown, the shifting
clutch 319 is designed as a friction clutch. In principle, a form-locking
clutch can also be used for this purpose. The internal combustion engine
303 drives at least one propeller 308 via the shifting clutch 319, the
transmission unit 322, and the thrust unit 321. The rotational direction
of the internal combustion engine 303 cannot be changed, and therefore
the rotational direction of the propeller 308 is also defined. In the
depiction, a propeller 308 is oriented toward the stern using the thrust
unit 321 and generates a propeller thrust directed astern, whereby the
ship moves in a forward travel direction 350. This motion is controlled
via a selector lever 365 which was moved within an adjustment range 360
for forward travel. If the intention now is to reverse the direction of
thrust of thrust unit 321, the selector lever 365 is moved in an
actuating direction opposite the actuating direction 360 into the
adjustment region 361 for travel in reverse. As a result, the thrust unit
321 is pivoted approximately 180° into a position diametrically
opposed to the position for forward travel, whereby the ship moves in the
reverse travel direction 351. To prevent a transverse force on the hull
330 resulting from the thrust force which pivots with the rotation of
thrust unit 321, it is possible to shut off the propeller 308 by
disengaging the shifting clutch 319 at the onset of the pivoting motion
of the thrust unit 321, and to re-engage it once the opposite position
has been reached.

[0059] The rotational speed of the internal combustion engine 303 or the
propeller 308 is reduced as the selector lever 365 moves toward a middle
position M. The signal for reversing the direction of thrust is received
by an electronic control unit (not depicted) when the selector lever 365
is moved from a first adjustment range 360, through the middle position
M, and into a second adjustment range 361. As a result, the shifting
clutch 319 is disengaged and then the thrust unit 321 is pivoted
approximately 180° via the control drive 329 into the opposite
position. Once the pivoting procedure--which is also referred to as
reversal in this context--has been completed, the shifting clutch 319 is
re-engaged. When the selector lever 365 is moved further, into the second
adjustment range, the rotational speed of the internal combustion engine
303 and the propeller 308 is increased once more, analogous to the
forward travel direction. Shifting behavior free of torque surges can be
attained using friction shifting clutch 319, when so actuated.

[0060] If the selector lever 365 is moved only into the middle position M,
the shifting clutch 319 disengages. If the information as to which
adjustment range the selector lever 365 was moved out of and into the
middle position M is stored in the electronic control unit, then, if the
selector lever is moved further, out of the middle position M and into
the opposite adjustment range, the electronic control unit recognizes the
request to reverse the direction of thrust, upon which the thrust unit
321 is pivoted approximately 180° by the control drive into a
second position, which is opposite the first position.

[0061] An alternative reversal of the direction of propulsion that does
not involve disengagement and engagement of the shifting clutch 319 is
attained using a method in which the rotational speed of the internal
combustion engine 303 and the propeller 308 is reduced when the selector
lever is moved toward the middle position M, and reaches a certain
minimum rotational speed in the middle position, preferably the idle
speed of the internal combustion engine 303. During the reversing
procedure, which also describes the pivoting motion of the thrust unit
321 approximately 180° into the opposite direction of thrust, the
unwanted thrust transverse to the longitudinal axis 480 (see FIGS. 10 and
11) remains limited to a minimum amount. The advantage thereof is that
the reversing procedure is shorter. In order to recognize the request to
reverse the direction of thrust, the reversing procedure can be triggered
only when the selector lever 365 is moved from the first adjustment range
360, through the middle position M, and into the second adjustment range
361. If the selector lever 365 is moved only into the middle position,
the shifting clutch disengages. Additional operating elements which are
not shown can be used to suppress the disengagement of the shifting
clutch 319.

[0062] FIG. 10 and FIG. 11 show, in a schematic top view of a ship, the
reversal of the propeller thrust from an arbitrary position of a thrust
unit 421. The reversing procedure proceeds analogously to the switch
between forward travel and reverse travel, as described with reference to
FIGS. 8 and 9. On the underside of a hull 430, the thrust unit 421 of a
pivotable ship propulsion system, which is also referred to as a rudder
propeller, can be pivoted about a substantially vertical control axis
420. In FIG. 10 the thrust unit is rotated about a steering angle 481 of
90° relative to the longitudinal direction 480 of the ship, and so
the thrust of the propeller 408 pushes the ship to the left in the
direction of motion 484. A direction of motion that is not in the
longitudinal direction is required for docking, for instance. If the
intention now is to brake this motion or reverse the direction of motion
484 into direction of motion 485, the thrust unit 421 is rotated about a
pivot angle 482 of approximately 180° into the opposite direction,
as depicted in FIG. 11, in order to reverse the direction of thrust of
the propeller 408. As a possible additional option, a cross jet propeller
470 is disposed in the region of the bow on the hull 430 shown, which
likewise can generate a thrust component transverse to the longitudinal
direction of the ship and thereby expand the maneuvering options. The
direction of thrust can be reversed from an arbitrary pivot angle 481 if
the thrust unit 421 is able to rotate freely, and if the thrust unit can
pivot at least 360°. A cross jet propeller in the region of the
stern for improving maneuverability can be omitted, which is
advantageous, since the direction of thrust is freely selectable.

[0063] FIG. 12 shows, by reference to a sectional drawing, an embodiment
of a drive device 509 which can be used to implement the method for
reversing the direction of thrust, which is described with reference to
FIGS. 8 to 11. A shifting clutch 519 for decoupling the driving internal
combustion engine from the propeller 508 is disposed on a transmission
unit 522. In this example, the shifting clutch 519 is in the form of a
friction clutch, thereby ensuring that engagement and disengagement is
comfortable and smooth. Couplings from the automotive industry can also
be used for this purpose, which is favorable in terms of cost. As an
alternative, a form-locking shifting clutch would also be feasible. A
thrust unit 521 is pivoted about a substantially vertical control axis
520 via a control drive 529, wherein the control drive 529 is in the form
of an electric motor in the example shown. As a possible alternative,
hydraulic actuation via a hydrostatic pump-motor system would be
feasible.